Yes, the show has done a good job at how evil he is but IMO he's more evil in the book. In the books he owns a pack of dogs.. "Ramsay's bitches." He would torture people and let them "escape" kinda like how he let Theon escape in the show. He would then take his pack of dogs and hunt them down. If he caught them, he would flay them, chop 'em up, and feed them to his dogs.

From the ASoiaF wiki: Ramsay openly enjoys abusive and sick practices such as having young women stripped naked and released into the Bolton forests, before hunting them with a pack of feral dogs. He gives a quick death to women who give him good sport (after raping them first), then flays their corpses. He likes to name his dogs after the women he enjoys most to "honor" them. The women who don't give him good sport are raped and then flayed alive. All the skins of his kills are brought back with him to the Dreadfort as gruesome trophies. The bodies of the woman are fed to his dogs.

He is miles more psychotic than Joffrey.

I think this says more about George RR Martin than anything Seriously dude, WTF!